Stage and plasma processing apparatus

ABSTRACT

A stage according to an exemplary embodiment has an electrostatic chuck. The electrostatic chuck has a base and a chuck main body. The chuck main body is provided on the base and configured to hold a substrate with electrostatic attractive force. The chuck main body has a plurality of first heaters and a plurality of second heaters. The number of second heaters is larger than the number of first heaters. The first heater controller drives the plurality of first heaters by an alternating current output or a direct current output from a first power source. The second heater controller drives the plurality of second heaters by an alternating current output or a direct current output from a second power source which has electric power lower than electric power of the output from the first power source.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/989,518 filed May 25, 2018 which is based on and claims priority fromJapanese Patent Application No. 2017-106736 filed on May 30, 2017, withthe Japan Patent Office, the disclosures of which are incorporatedherein in their entirety by reference.

TECHNICAL FIELD

An exemplary embodiment of the present disclosure relates to a stage anda plasma processing apparatus.

BACKGROUND

A plasma processing apparatus is used to manufacture an electronicdevice such as a semiconductor device. In general, the plasma processingapparatus has a chamber main body and a stage. The chamber main bodyprovides an internal space thereof as a chamber. The stage is providedin the chamber. The stage is configured to support a substrate placed onthe stage.

The stage includes an electrostatic chuck. The electrostatic chuck has abase and a chuck main body. A high-frequency power source is connectedto the base. The chuck main body is provided on the base. The chuck mainbody is configured to generate electrostatic attractive force betweenthe chuck main body and the substrate placed on the chuck main body,thereby holding the substrate using the generated electrostaticattractive force.

An in-plane temperature distribution of the substrate is important tothe plasma processing performed using the plasma processing apparatus.Therefore, the stage needs to control the in-plane temperaturedistribution of the substrate. A plurality of heaters (resistanceheating heaters) are provided in the chuck main body in order to controlthe in-plane temperature distribution of the substrate. The plurality ofheaters are driven by alternating current from an alternating currentpower source. Japanese Patent Laid-Open Publication No. 2016-006875discloses a plasma processing apparatus having the aforementioned stage.

SUMMARY

In one aspect, a stage for a plasma processing apparatus is provided.The stage has a power feeding unit and an electrostatic chuck. The powersupply unit provides a transmission path for transmitting high-frequencywaves from the high-frequency power source. The electrostatic chuck hasa base and a chuck main body. The base has conductivity, is provided onthe power feeding unit, and is electrically connected to the powerfeeding unit. The chuck main body is provided on the base and configuredto hold a substrate with electrostatic attractive force. The chuck mainbody has a plurality of first heaters and a plurality of second heaters.The plurality of first heaters are provided in the chuck main body so asto be distributed on a plane in the chuck main body which is orthogonalto a central axis of the chuck main body. The number of second heatersis larger than the number of first heaters. The plurality of secondheaters are provided in the chuck main body so as to be distributed on aseparate plane in the chuck main body which is orthogonal to a centralaxis of the chuck main body. The stage further includes a first heatercontroller and a second heater controller. The first heater controlleris configured to drive the plurality of first heaters by an alternatingcurrent output or a direct current output from a first power source. Thesecond heater controller is configured to drive the plurality of secondheaters by an alternating current output or a direct current output froma second power source which has electric power lower than electric powerof the output from the first power source.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects, embodiments,and features described above, further aspects, embodiments, and featureswill become apparent by reference to the drawings and the followingdetailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view schematically illustrating a plasma processingapparatus according to an exemplary embodiment.

FIG. 2 is a cross-sectional view of a stage according to the exemplaryembodiment.

FIG. 3 is a view schematically illustrating the stage according to theexemplary embodiment together with other constituent components of theplasma processing apparatus.

FIG. 4 is a top plan view illustrating an example of a layout of aplurality of first heaters of the stage illustrated in FIG. 2.

FIG. 5 is a top plan view illustrating an example of a layout of aplurality of second heaters of the stage illustrated in FIG. 2.

FIG. 6 is a top plan view illustrating an example of a layout ofterminals on a rear surface of a chuck main body of the stageillustrated in FIG. 2.

FIG. 7 is a view illustrating a configuration related to control of thestage illustrated in FIG. 2.

FIG. 8 is a view for explaining a technique for obtaining a function ofconverting a temperature increase amount caused by each of the pluralityof second heaters into a power amount per predetermined time of each ofa plurality of second outputs to be supplied to the plurality of secondheaters.

DESCRIPTION OF EMBODIMENT

In the following detailed description, reference is made to theaccompanying drawing, which form a part hereof. The illustrativeembodiments described in the detailed description, drawing, and claimsare not meant to be limiting. Other embodiments may be utilized, andother changes may be made without departing from the spirit or scope ofthe subject matter presented here.

It is necessary to provide the plurality of heaters in the chuck mainbody in order to improve controllability of the in-plane temperaturedistribution of the substrate. As the number of heaters is increased,the number of power feeding lines for supplying alternating currentoutputs to the heaters is increased, and a rated electric current ofeach of the power feeding lines is decreased. Therefore, power of thealternating current output to be supplied to each of the heaters isdecreased, and a temperature range, which may be set by each of theheaters, is narrowed. In consideration of this background, there is aneed for a stage having a wide settable temperature range and capable ofprecisely controlling the in-plane temperature distribution of thesubstrate.

In one aspect, a stage for a plasma processing apparatus is provided.The stage has a power feeding unit and an electrostatic chuck. The powerfeeding unit provides a transmission path for transmittinghigh-frequency waves from the high-frequency power source. Theelectrostatic chuck has a base and a chuck main body. The base hasconductivity, is provided on the power feeding unit, and is electricallyconnected to the power feeding unit. The chuck main body is provided onthe base and configured to hold a substrate with electrostaticattractive force. The chuck main body has a plurality of first heatersand a plurality of second heaters. The plurality of first heaters areprovided in the chuck main body so as to be distributed on a plane inthe chuck main body which is orthogonal to a central axis of the chuckmain body. The number second heaters is larger than the number of firstheaters. The plurality of second heaters are provided in the chuck mainbody so as to be distributed on a separate plane in the chuck main bodywhich is orthogonal to a central axis of the chuck main body. The stagefurther includes a first heater controller and a second heatercontroller. The first heater controller is configured to drive theplurality of first heaters by an alternating current output or a directcurrent output from a first power source. The second heater controlleris configured to drive the plurality of second heaters by an alternatingcurrent output or a direct current output from a second power sourcewhich has electric power lower than electric power of the output fromthe first power source.

In the stage according to the aspect, the number of first heaters issmaller than the number of second heaters. That is, the number of firstheaters is comparatively small. Therefore, the number of power feedinglines for the plurality of first heaters is decreased, and a ratedelectric current of each of the power feeding lines is increased. Forthis reason, a settable electric power range of the outputs to besupplied to the plurality of first heaters is widened, and a settabletemperature range is widened. In addition, each of the comparativelyplurality of second heaters may be driven by the output havingcomparatively low electric power. Therefore, the plurality of secondheaters may precisely control the in-plane temperature distribution ofthe substrate even though each of the plurality of second heaters has anarrow settable temperature range. Since the stage according to theaspect has the plurality of first heaters and the plurality of secondheaters, a temperature range settable by the stage is wide, and thestage may precisely control the in-plane temperature distribution of thesubstrate.

In one exemplary embodiment, the first heater controller is configuredto drive the plurality of first heaters by the alternating current ofthe alternating current output from the first power source. The secondheater controller is configured to drive the plurality of second heatersby the direct current of the direct current output from the second powersource.

In one exemplary embodiment, the plurality of first heaters are providedcoaxially with respect to a central axis of the chuck main body. Theplurality of second heaters are provided in a central zone whichintersects the central axis of the chuck main body and the plurality ofzones which surround the central zone and are arranged in thecircumferential direction within the plurality of regions coaxial withthe central axis of the chuck main body. According to the exemplaryembodiment, a temperature distribution in a radial direction of thesubstrate is controlled by the plurality of first heaters, andtemperature distributions in the radial direction and a circumferentialdirection of the substrate are controlled by the plurality of secondheaters.

In one exemplary embodiment, the chuck main body has a rear surfacewhich is a surface facing the base, and an upper surface which is asurface opposite to the rear surface. The plurality of second heatersare provided between the plurality of first heaters and the uppersurface. In this exemplary embodiment, the plurality of second heatersare closer to the upper surface of the chuck main body, that is, thesurface on which the substrate is placed than the plurality of firstheaters are to the upper surface of the chuck main body. Therefore, itis possible to further improve controllability of the in-planetemperature distribution of the substrate.

In one exemplary embodiment, the stage further includes a plurality offirst power feeding lines and a plurality of second power feeding lines.The plurality of first power feeding lines are electrically connected tothe plurality of first heaters, respectively. The plurality of secondpower feeding lines are electrically connected to the plurality ofsecond heaters, respectively. The first heater controller is configuredto produce a plurality of first outputs by distributing the output ofthe first power source and to supply the plurality of first outputs,which have individually adjusted power amounts, to the plurality offirst heaters through the plurality of first power feeding lines. Thesecond heater controller is configured to produce a plurality of secondoutputs by distributing the output of the second power source and tosupply the plurality of second outputs, which have individually adjustedpower amounts, to the plurality of second heaters through the pluralityof second power feeding lines. The power feeding unit defines anaccommodation space surrounded by the transmission path. The pluralityof first power feeding lines, the first heater controller, the pluralityof second power feeding lines, and the second heater controller aredisposed in the accommodation space. According to this exemplaryembodiment, since the output is distributed to the plurality of firstheaters in the accommodation space surrounded by the transmission path,the number of filters, which are required to inhibit an inflow of thehigh-frequency waves to the first power source from the stage, may bereduced. In addition, since the output is distributed to the pluralityof second heaters in the accommodation space surrounded by thetransmission path, the number of filters, which are required to inhibitan inflow of the high-frequency waves to the second power source fromthe stage, may be reduced. Therefore, deterioration in impedanceproperties of the filter is inhibited, and a loss of the high-frequencywaves is inhibited.

In one exemplary embodiment, the plurality of first outputs havesubstantially the same and constant electric power, and the first heatercontroller is configured to control a plurality of first duty ratioswhich are ratios of supply durations for which the plurality of firstoutputs are supplied to the plurality of first heaters, respectively,relative to a predetermined duration. The plurality of second outputshave substantially the same and constant electric power, and the secondheater controller is configured to control a plurality of second dutyratios which are ratios of supply durations for which the plurality ofsecond outputs are supplied to the plurality of second heaters,respectively, relative to a predetermined duration. In this exemplaryembodiment, the power amounts of the plurality of first outputs fordriving the plurality of first heaters are adjusted by the plurality offirst duty ratios, respectively, and the power amounts of the pluralityof second outputs for driving the plurality of second heaters areadjusted by the plurality of second duty ratios, respectively. Accordingto this exemplary embodiment, it is possible to adjust the power amountsof the plurality of second outputs for driving the plurality of secondheaters without mounting a plurality of power control circuits (e.g.,DC/DC converters) in the second heater controller.

In one exemplary embodiment, the stage further includes a plurality oftemperature sensors provided to measure temperatures of the plurality ofzones in which the plurality of first heaters are disposed. The firstheater controller is configured to adjust the plurality of first dutyratios so as to reduce an error between a target temperature and ameasured value of a temperature measured by each of the plurality oftemperature sensors or to reduce an error between the target temperatureand a moving average value obtained from time-series data of themeasured value of the temperature measured by each of the plurality oftemperature sensors. The second heater controller is configured toadjust the plurality of second duty ratios so as to reduce an errorbetween a target value and the product of the measured value of electricpower of each of the plurality of second outputs and the correspondingsecond duty ratio among the plurality of second duty ratios or to reducean error between the target value and a moving average value obtainedfrom time-series data of the product of the measured value of electricpower of each of the plurality of second outputs and the correspondingsecond duty ratio. In this exemplary embodiment, the plurality of secondoutputs to be supplied to the plurality of second heaters are controlledbased on the product of the measured value of electric power and thesecond duty ratio or based on the moving average value, instead of basedon the measured values of the temperatures of the zones in which theplurality of second heaters are disposed. Therefore, the number oftemperature sensors to be provided in the stage is reduced.

In one exemplary embodiment, the chuck main body has a substratemounting region in which the substrate is placed, and an outercircumferential region which surrounds the substrate mounting regionfrom the outside in the radial direction with respect to the centralaxis. A plurality of terminals, which are electrically connected to theplurality of first power feeding lines and the plurality of second powerfeeding lines, are provided within the outer circumferential region. Theplurality of terminals are undesirable temperature properties in termsof controlling the temperature of the substrate. In this exemplaryembodiment, the plurality of terminals are provided within the outercircumferential region, and no terminal is provided within the substratemounting region, such that influences of the plurality of terminals onthe control of the temperature of the substrate are inhibited.

In one exemplary embodiment, the plurality of terminals are distributedaround the entire circumference of the outer circumferential region.

In one exemplary embodiment, the plurality of second heaters areprovided within the substrate mounting region, and some of the pluralityof first heaters are provided at least within the outer circumferentialregion.

According to another aspect, a plasma processing apparatus is provided.The plasma processing apparatus includes a chamber main body whichprovides a chamber, any of the stages according to the aforementionedaspect and the aforementioned various exemplary embodiments, and ahigh-frequency power source. The electrostatic chuck is provided in thechamber. The high-frequency power source is electrically connected tothe power feeding unit.

In one exemplary embodiment, the plasma processing apparatus furtherincludes a first filter and a second filter. The first filter inhibitsan inflow of high-frequency waves to the first power source. The firstfilter partially constitutes a power feeding line between the firstpower source and the first heater controller and is provided outside thepower feeding unit with respect to the accommodation space. The secondfilter inhibits an inflow of high-frequency waves to the second powersource. The second filter partially constitutes a power feeding linebetween the second power source and the second heater controller and isprovided outside the power feeding unit with respect to theaccommodation space.

As described above, there is provided the stage having a wide settabletemperature range and capable of precisely controlling the in-planetemperature distribution of the substrate.

Hereinafter, various exemplary embodiments will be described in detailwith reference to the drawings. Further, in the respective drawings,like reference numerals denote like parts or corresponding parts.

FIG. 1 is a view schematically illustrating a plasma processingapparatus according to an exemplary embodiment. FIG. 1 schematicallyillustrates a longitudinal sectional structure of a plasma processingapparatus 10 according to an exemplary embodiment. The plasma processingapparatus 10 illustrated in FIG. 1 is a capacitively coupled plasmaprocessing apparatus.

The plasma processing apparatus 10 has a chamber main body 12. Thechamber main body 12 has a roughly cylindrical shape. The chamber mainbody 12 provides an internal space thereof as a chamber 12 c. Thechamber main body 12 is made of, for example, aluminum. The chamber mainbody 12 is connected to ground potential. A plasma-resistant film isformed on an inner wall surface of the chamber main body 12, that is, awall surface that defines the chamber 12 c. The film may be a filmformed by an anodization treatment or a ceramic film such as a film madeof an yttrium oxide. A passageway 12 g is formed in a sidewall of thechamber main body 12. A substrate W passes through the passageway 12 gwhen the substrate W is loaded into the chamber 12 c and when thesubstrate W is unloaded from the chamber 12 c. A gate valve 14 ismounted on the sidewall of the chamber main body 12. The passageway 12 gis openable or closable by the gate valve 14.

In the chamber 12 c, a support unit 15 extends upward from a bottomportion of the chamber main body 12. The support unit 15 has a roughlycylindrical shape and is made of an insulating material such as quartz.A stage 16 is placed on the support unit 15. The stage 16 is supportedby the support unit 15.

The stage 16 is configured to support the substrate W in the chamber 12c. The stage 16 includes a power feeding unit 18 and an electrostaticchuck 20. The power feeding unit 18 provides a transmission path fortransmitting high-frequency waves from a high-frequency power source tobe described below. The electrostatic chuck 20 is provided on the powerfeeding unit 18. The electrostatic chuck 20 includes a base 22 and achuck main body 26. The base 22 has conductivity and constitutes a lowerelectrode. The base 22 is provided on the power feeding unit 18 andelectrically connected to the power feeding unit 18.

A flow path 22 f is provided in the base 22. The flow path 22 f is aflow path for a heat exchange medium. The heat exchange medium is, forexample, a refrigerant. The heat exchange medium is supplied to the flowpath 22 f from a chiller unit TU provided outside the chamber main body12. The heat exchange medium supplied to the flow path 22 f returns backto the chiller unit TU. As described above, the heat exchange medium issupplied to the flow path 22 f so that the heat exchange mediumcirculates between the flow path 22 f and the chiller unit.

The chuck main body 26 is provided on the base 22. The chuck main body26 is fixed to the base 22 by, for example, an adhesive. The chuck mainbody 26 is configured to hold the substrate W with electrostaticattractive force. An electrode 26 a is provided in the chuck main body26 (see FIG. 2). The electrode 26 a is a film-shaped electrode. A directcurrent power source DSC is connected to the electrode 26 a via a switchSWC. When voltage is applied to the electrode 26 a from the directcurrent power source DSC, the electrostatic attractive force isgenerated between the chuck main body 26 and the substrate W placed onthe chuck main body 26. The substrate W is attracted to the chuck mainbody 26 by the generated electrostatic attractive force, and thesubstrate W is held by the chuck main body 26. In addition, the plasmaprocessing apparatus 10 provides a gas supply line for supplying a heattransfer gas, for example, He gas between an upper surface of the chuckmain body 26 and a rear surface of the substrate W from a gas supplymechanism.

A cylindrical portion 28 extends upward from the bottom portion of thechamber main body 12. The cylindrical portion 28 extends along an outercircumference of the support unit 15. The cylindrical portion 28 hasconductivity and has a roughly cylindrical shape. The cylindricalportion 28 is connected to ground potential. An insulating unit 29 isprovided on the support unit 15. The insulating unit 29 has aninsulation property and is made of ceramics such as quartz. Theinsulating unit 29 has a roughly cylindrical shape and extends along anouter circumference of the power feeding unit 18 and an outercircumference of the electrostatic chuck 20. A focus ring FR is mountedwithin outer circumferential regions of the base 22 and the chuck mainbody 26. The focus ring FR has a roughly annular plate shape and is madeof, for example, silicon or a silicon oxide. The focus ring FR isprovided to surround an edge of a substrate mounting region of the chuckmain body 26 and surround an edge of the substrate W.

The plasma processing apparatus 10 further includes an upper electrode30. The upper electrode 30 is provided above the stage 16. The upperelectrode 30, together with a member 32, closes an upper opening of thechamber main body 12. The member 32 has an insulation property. Theupper electrode 30 is supported at an upper side of the chamber mainbody 12 by the member 32.

The upper electrode 30 includes a top plate 34 and a support body 36. Alower surface of the top plate 34 defines the chamber 12 c. A pluralityof gas discharge holes 34 a are provided in the top plate 34. Each ofthe plurality of gas discharge holes 34 a penetrates the top plate 34 ina plate thickness direction (vertical direction). The top plate 34 ismade of, but not limited to, for example, silicon. Alternatively, thetop plate 34 may have a structure in which a plasma-resistant film isprovided on a surface of a base material made of aluminum. The film maybe a film formed by an anodization treatment or a ceramic film such as afilm made of an yttrium oxide.

The support body 36 is a component for supporting the top plate 34 sothat the top plate 34 is detachably mounted. The support body 36 may bemade of an electrically conductive material such as, for example,aluminum. A gas diffusion chamber 36 a is provided in the support body36. A plurality of gas holes 36 b extend downward from the gas diffusionchamber 36 a. The plurality of gas holes 36 b communicate with theplurality of gas discharge holes 34 a, respectively. A gas introducingport 36 c, which guides gas into the gas diffusion chamber 36 a, isformed in the support body 36, and a gas supply pipe 38 is connected tothe gas introducing port 36 c.

A gas source group 40 is connected to the gas supply pipe 38 via a valvegroup 42 and a flow rate controller group 44. The gas source group 40includes a plurality of gas sources. The valve group 42 includes aplurality of valves, and the flow rate controller group 44 includes aplurality of flow rate controllers. Each of the plurality of flow ratecontrollers of the flow rate controller group 44 is a mass flowcontroller or a pressure-control flow rate controller. Each of theplurality of gas sources of the gas source group 40 is connected to thegas supply pipe 38 via the corresponding valve of the valve group 42 andthe corresponding flow rate controller of the flow rate controller group44. The plasma processing apparatus 10 may supply the chamber 12 c withgas from one or more gas sources selected from the plurality of gassources of the gas source group 40 at an individually adjusted flowrate.

A baffle plate 48 is provided between the cylindrical portion 28 and thesidewall of the chamber main body 12. The baffle plate 48 may beconfigured by, for example, coating a base material made of aluminumwith ceramics such as an yttrium oxide. A plurality of through holes areformed in the baffle plate 48. Below the baffle plate 48, a gasdischarge pipe 52 is connected to the bottom portion of the chamber mainbody 12. A gas discharge device 50 is connected to the gas dischargepipe 52. The gas discharge device 50 has a pressure controller such asan automatic pressure control valve, and a vacuum pump such as a turbomolecular pump, and may reduce pressure in the chamber 12 c.

The plasma processing apparatus 10 further includes a firsthigh-frequency power source 62. The first high-frequency power source 62is a power source that generates first high-frequency waves forgenerating plasma. The first high-frequency waves have a frequencyranging from 27 to 100 MHz, for example, a frequency of 60 MHz. Thefirst high-frequency power source 62 is connected to the upper electrode30 via a matching device 63. The matching device 63 has a circuit formatching output impedance of the first high-frequency power source 62with impedance at a load side (upper electrode 30 side). Further, thefirst high-frequency power source 62 may be connected to the powerfeeding unit 18 via the matching device 63. The upper electrode 30 isconnected to the ground potential in the case in which the firsthigh-frequency power source 62 is connected to the power feeding unit18.

The plasma processing apparatus 10 further includes a secondhigh-frequency power source 64. The second high-frequency power source64 is a power source that generates second high-frequency bias waves forputting ions into the substrate W. The frequency of the secondhigh-frequency waves is lower than the frequency of the firsthigh-frequency waves. The second high-frequency waves have a frequencyranging from 400 kHz to 13.56 MHz, for example, a frequency of 400 kHz.The second high-frequency power source 64 is connected to the powerfeeding unit 18 via a matching device 65 and a power supplier 66. Thematching device 65 has a circuit for matching output impedance of thesecond high-frequency power source 64 with impedance at the load side(power feeding unit 18 side).

In one exemplary embodiment, the plasma processing apparatus 10 mayfurther include a main control unit MC. The main control unit MC is acomputer having a processor, a storage device, an input device, adisplay device, and the like, and controls respective parts of theplasma processing apparatus 10. Specifically, the main control unit MCexecutes a control program stored in the storage device and controlsrespective parts of the plasma processing apparatus 10 based on recipedata stored in the storage device. Therefore, the plasma processingapparatus 10 is configured to perform a process assigned based on therecipe data.

Hereinafter, the stage 16 will be described in detail. FIG. 2 is across-sectional view of the stage according to the exemplary embodiment.FIG. 3 is a view schematically illustrating the stage according to theexemplary embodiment together with other constituent components of theplasma processing apparatus. As illustrated in FIGS. 2 and 3, the stage16 has the power feeding unit 18 and the electrostatic chuck 20.

As described above, the power feeding unit 18 provides a transmissionpath for the high-frequency waves from the high-frequency power source(e.g., second high-frequency power source 64). The power feeding unit 18has conductivity and is made of, for example, metal. The aforementionedpower supplier 66 is connected to the power feeding unit 18. In oneexemplary embodiment, the power feeding unit 18 provides an internalspace thereof as an accommodation space 18 s.

In one exemplary embodiment, the power feeding unit 18 has a firstmember 18 a, a second member 18 b, and a third member 18 c. The firstmember 18 a, the second member 18 b, and the third member 18 c haveconductivity and are made of, for example, metal. The first member 18 ais a member having a roughly circular shape in a plan view, and acentral portion of the first member 18 a protrudes downward. The powersupplier 66 is connected to the central portion of the first member 18a. The second member 18 b is mounted on the first member 18 a andconnected to the first member 18 a. The second member 18 b has a roughlyring shape. The third member 18 c is mounted on the second member 18 band connected to the second member 18 b. The third member 18 c has aroughly disk shape. The first member 18 a, the second member 18 b, andthe third member 18 c constitute a transmission path for thehigh-frequency waves. The assembly including the first member 18 a, thesecond member 18 b, and the third member 18 c defines the accommodationspace 18 s.

The electrostatic chuck 20 is provided on the power feeding unit 18. Asdescribed above, the electrostatic chuck 20 has the base 22 and thechuck main body 26. The base 22 has a roughly disk shape. As describedabove, the flow path 22 f for the heat exchange medium is formed in thebase 22. The base 22 has conductivity and is made of metal such asaluminum. The base 22 is provided on the power feeding unit 18 andelectrically connected to the power feeding unit 18. The base 22constitutes the lower electrode of the plasma processing apparatus 10.

The chuck main body 26 is provided on the base 22. The chuck main body26 is fixed to the upper surface of the base 22 by, for example, anadhesive. The chuck main body 26 has a ceramic main body 260. Theceramic main body 260 is made of ceramics and has a roughly disk shape.

The ceramic main body 260 has a substrate mounting region 260 a and anouter circumferential region 260 b. The substrate mounting region 260 ais a roughly disk-shaped region. An upper surface of the substratemounting region 260 a is an upper surface of the chuck main body 26 onwhich the substrate W is placed. The outer circumferential region 260 bis a roughly annular plate-shaped region and extends to surround thesubstrate mounting region 260 a. That is, the outer circumferentialregion 260 b extends, outside the substrate mounting region 260 a, in acircumferential direction with respect to a central axis AX of the chuckmain body 26 and the ceramic main body 260. The substrate mountingregion 260 a and the outer circumferential region 260 b provide acontinuous flat lower surface (rear surface) of the chuck main body 26.In the vicinity of a rear surface of the chuck main body 26, an uppersurface of the outer circumferential region 260 b extends further thanthe upper surface of the substrate mounting region 260 a. As illustratedin FIG. 1, the focus ring FR is mounted within the outer circumferentialregion 260 b.

The chuck main body 26 has the electrode 26 a, a plurality of firstheaters 26 b, and a plurality of second heaters 26 c. The electrode 26 aextends in a direction orthogonal to the central axis AX in thesubstrate mounting region 260 a. Each of the plurality of first heaters26 b and the plurality of second heaters 26 c is a thin film resistanceheater. The plurality of first heaters 26 b and the plurality of secondheaters 26 c are provided in the ceramic main body 260. The plurality offirst heaters 26 b and the plurality of second heaters 26 c are providedbetween the electrode 26 a and the rear surface of the chuck main body26. The plurality of first heaters 26 b are distributed on a plane inthe chuck main body 26 which is orthogonal to the central axis AX. Thenumber of second heaters 26 c is larger than the number of first heaters26 b. The plurality of second heaters 26 c are distributed on a separateplane in the chuck main body 26 which is orthogonal to the central axisAX.

FIG. 4 is a top plan view illustrating an example of a layout of theplurality of first heaters of the stage illustrated in FIG. 2. FIG. 4illustrates a layout of the plurality of first heaters 26 b in the planeorthogonal to the central axis AX. As illustrated in FIG. 4, in oneexemplary embodiment, the plurality of first heaters 26 b are providedcoaxially with respect to the central axis AX. Specifically, a planeshape of the first heater 26 b, which is provided at a center among theplurality of first heaters 26 b, is a circular shape. Another firstheater 26 b has an annular shape that surrounds the first heater 26 bprovided at the center. That is, the other first heaters 26 b except forthe first heater 26 b provided at the center have a band shape extendingin the circumferential direction. In one exemplary embodiment, some ofthe plurality of first heaters 26 b are provided at least within theouter circumferential region 260 b. For example, among the plurality offirst heaters 26 b, the first heater 26 b, which extends at theoutermost side with respect to the central axis AX, is provided withinthe outer circumferential region 260 b, and the other first heaters 26 bare provided within the substrate mounting region 260 a. The pluralityof first heaters 26 b heat a plurality of zones Z1 in which theplurality of first heaters 26 b are disposed, respectively.

The plurality of first heaters 26 b may also be arranged in thecircumferential direction with respect to the central axis AX. That is,the plurality of zones Z1 may have a central zone, and a plurality ofzones which are arranged in the circumferential direction within theplurality of coaxial regions outside the central zone, and the pluralityof first heaters 26 b may be provided in the plurality of zones Z1,respectively.

FIG. 5 is a top plan view illustrating an example of a layout of theplurality of second heaters of the stage illustrated in FIG. 2. FIG. 5illustrates a layout of the plurality of second heaters 26 c in theplane orthogonal to the central axis AX. The plurality of second heaters26 c are provided to be distributed within the substrate mounting region260 a. As illustrated in FIG. 5, as an example, the plurality of secondheaters 26 c are provided in a plurality of zones Z2, respectively. Theplurality of zones Z2 include a central zone which intersects thecentral axis AX, and a plurality of zones which are arranged in thecircumferential direction within a plurality of regions coaxial withrespect to the central axis AX. Further, the plurality of zones Z2, thatis, the plurality of second heaters 26 c are included within any of theplurality of zones Z1.

As illustrated in FIGS. 2 and 3, the plurality of second heaters 26 care provided between the plurality of first heaters 26 b and the uppersurface of the chuck main body 26 (i.e., the upper surface of thesubstrate mounting region 260 a). That is, the plurality of secondheaters 26 c are provided above the plurality of first heaters 26 b.Further, the plurality of second heaters 26 c may be provided below theplurality of first heaters 26 b.

The plurality of first heaters 26 b generate heat by being driven by anoutput from a first power source 80. The output of the first powersource 80 is an alternating current output or a direct current output.That is, the output of the first power source 80 may be any one of analternating current output and a direct current output. The plurality ofsecond heaters 26 c generate heat by being driven by an output from asecond power source 82. The output of the second power source 82 is analternating current output or a direct current output. That is, theoutput of the second power source 82 may be any one of an alternatingcurrent output and a direct current output. In one exemplary embodiment,the plurality of first heaters 26 b are driven by an alternating currentof the alternating current output from the first power source, and theplurality of second heaters 26 c are driven by a direct current of thedirect current output from the second power source. The stage 16 has afirst heater controller 71 and a second heater controller 72 in order todrive the plurality of first heaters 26 b and the plurality of secondheaters 26 c. Hereinafter, the reference is made to FIGS. 6 and 7together with FIGS. 2 and 3. FIG. 6 is a top plan view illustrating anexample of a layout of terminals on the rear surface of the chuck mainbody of the stage illustrated in FIG. 2. FIG. 7 is a view illustrating aconfiguration related to control of the stage illustrated in FIG. 2.

A plurality of first power feeding lines 73 are electrically connectedto the plurality of first heaters 26 b, respectively. The pair of firstpower feeding lines 73 is connected to the plurality of first heaters 26b, respectively. A plurality of second power feeding lines 74 areelectrically connected to the plurality of second heaters 26 c,respectively. The pair of second power feeding lines 74 is connected tothe plurality of second heaters 26 c, respectively. In the one exemplaryembodiment, the plurality of second power feeding lines 74 may beprovided by a plurality of flexible printed circuit boards. Each of theplurality of flexible printed circuit boards provides the severalcorresponding second power feeding lines 74 among the plurality ofsecond power feeding lines 74. In one exemplary embodiment, the firstheater controller 71, the plurality of first power feeding lines 73, thesecond heater controller 72, and the plurality of second power feedinglines 74 are provided in the accommodation space 18 s.

As illustrated in FIG. 6, a plurality of terminals 26 e and a pluralityof terminals 26 f are provided on the rear surface of the chuck mainbody 26. The plurality of first power feeding lines 73 are connected tothe plurality of terminals 26 e, respectively. The plurality ofterminals 26 e are connected to the plurality of first heaters 26 bthrough inner wires in the chuck main body 26. The plurality of secondpower feeding lines 74 are connected to the plurality of terminals 26 f,respectively. In a case in which the plurality of second power feedinglines 74 are provided by the plurality of flexible printed circuitboards, the plurality of terminals 26 f are grouped as a plurality ofterminal groups. The plurality of terminals 26 f are connected to theplurality of second heaters 26 c through inner wires in the chuck mainbody 26. In one exemplary embodiment, the plurality of terminals 26 eand the plurality of terminals 26 f are provided within the outercircumferential region 260 b. In one exemplary embodiment, the pluralityof terminals 26 e and the plurality of terminals 26 f (or the pluralityof terminal groups) are distributed in the circumferential directionaround the entire circumference of the outer circumferential region 260b.

The plurality of first power feeding lines 73 are connected to the firstheater controller 71. The first heater controller 71 is connected to thefirst power source 80. The first heater controller 71 is configured todrive the plurality of first heaters 26 b by the output from the firstpower source 80. In one exemplary embodiment, the first heatercontroller 71 is configured to drive the plurality of first heaters 26 bby a plurality of first outputs produced by distributing the output fromthe first power source 80. The first heater controller 71 supplies theplurality of first outputs to the plurality of first heaters 26 bthrough the plurality of first power feeding lines 73 in order to drivethe plurality of first heaters 26 b. The first heater controller 71 isconfigured to individually adjust power amounts of the plurality offirst outputs to be supplied to the plurality of first heaters 26 b. Inone exemplary embodiment, the output from the first power source 80 isan alternating current output, and the first heater controller 71 isconfigured to drive the plurality of first heaters 26 b by analternating current of the plurality of first outputs which arealternating current outputs.

The plurality of second power feeding lines 74 are connected to thesecond heater controller 72. The second heater controller 72 isconnected to the second power source 82. The second heater controller 72is configured to drive the plurality of second heaters 26 c by theoutput from the second power source 82. In one exemplary embodiment, thesecond heater controller 72 is configured to drive the plurality ofsecond heaters 26 c by a plurality of second outputs produced bydistributing the output from the second power source 82. Electric powerfor driving the plurality of second heaters 26 c is lower than electricpower for driving the plurality of first heaters 26 b. The second heatercontroller 72 supplies the plurality of second outputs to the pluralityof second heaters 26 c through the plurality of second power feedinglines 74 in order to drive the plurality of second heaters 26 c. Thesecond heater controller 72 is configured to individually adjust poweramounts of the plurality of second outputs to be supplied to theplurality of second heaters 26 c.

In one exemplary embodiment, the output from the second power source 82is a direct current output, and the second heater controller 72 isconfigured to drive the plurality of second heaters 26 c by a directcurrent of the plurality of second outputs which are direct currentoutputs. In a case in which the first power source 80 is an alternatingcurrent power source and the second power source 82 is a direct currentpower source, the second power source 82 is connected to the first powersource 80 as illustrated. In this case, the second power source 82 is anAC/DC converter for converting the alternating current output from thefirst power source 80 into a direct current, and for example, the secondpower source 82 is a switching power source.

As illustrated in FIG. 7, a plurality of wires 71 f and a plurality ofwires 71 r are provided in the first heater controller 71. One end ofeach of the plurality of wires 71 f is connected to the correspondingfirst heater 26 b, among the plurality of first heaters 26 b, throughthe corresponding first power feeding line 73 among the plurality offirst power feeding lines 73. One end of each of the plurality of wires71 r is connected to the corresponding first heater 26 b, among theplurality of first heaters 26 b, through the corresponding first powerfeeding line 73 among the plurality of first power feeding lines 73.

The other end of each of the plurality of wires 71 f is connected to thefirst power source 80 via a filter F11 (first filter). Specifically, theother end of each of the plurality of wires 71 f is connected to aterminal ET11 illustrated in FIG. 2, and the terminal ET11 is connectedto a terminal FT11 of a filter unit FU. The filter unit FU has thefilter F11, a filter F12 (first filter), a filter F21 (second filter),and a filter F22 (second filter). The filter unit FU including thefilter F11, the filter F12, the filter F21, and the filter F22 isprovided outside the power feeding unit 18 with respect to theaforementioned accommodation space 18 s.

The terminal FT11 is connected to the filter F11. The filter F11inhibits an inflow of the high-frequency waves to the first power source80. The filter F11 is, for example, an LC filter. The terminal FT11 isconnected to one end of a coil of the filter F11. The coil of the filterF11 partially constitutes a power feeding line between the first powersource 80 and the first heater controller 71. The other end of the coilof the filter F11 is connected to the ground through a condenser of thefilter F11.

The other end of each of the plurality of wires 71 r is connected to thefirst power source 80 via the filter F12. Specifically, the other end ofeach of the plurality of wires 71 r is connected to a terminal ET12illustrated in FIG. 2, and the terminal ET12 is connected to a terminalFT12 of the filter unit FU. The terminal FT12 is connected to the filterF12. The filter F12 inhibits an inflow of the high-frequency waves tothe first power source 80. The filter F12 is, for example, an LC filter.The terminal FT12 is connected to one end of a coil of the filter F12.The coil of the filter F12 partially constitutes a wire between thefirst power source 80 and the first heater controller 71. The other endof the coil of the filter F12 is connected to the ground through acondenser of the filter F12.

As illustrated in FIG. 7, a plurality of wires 72 p and a plurality ofwires 72 g are provided in the second heater controller 72. One end ofeach of the plurality of wires 72 p is connected to the correspondingsecond heater 26 c, among the plurality of second heaters 26 c, throughthe corresponding second power feeding line 74 among the plurality ofsecond power feeding lines 74. One end of each of the plurality of wires72 g is connected to the corresponding second heater 26 c, among theplurality of second heaters 26 c, through the corresponding second powerfeeding line 74 among the plurality of second power feeding lines 74.

The other end of each of the plurality of wires 72 p is connected to thesecond power source 82 via the filter F21. Specifically, the other endof each of the plurality of wires 72 p is connected to a terminal ET21illustrated in FIG. 2, and the terminal ET21 is connected to a terminalFT21 of the filter unit FU. The terminal FT21 is connected to the filterF21. The filter F21 inhibits an inflow of the high-frequency waves tothe second power source 82. The filter F21 is, for example, an LCfilter. The terminal FT21 is connected to one end of a coil of thefilter F21. The coil of the filter F21 partially constitutes a powerfeeding line between the second power source 82 and the second heatercontroller 72. The other end of the coil of the filter F21 is connectedto the ground through a condenser of the filter F21.

The other end of each of the plurality of wires 72 g is connected to thesecond power source 82 via the filter F22. Specifically, the other endof each of the plurality of wires 72 g is connected to a separateterminal, and the separate terminal is connected to a separate terminalof the filter unit FU. The separate terminal of the filter unit FU isconnected to the filter F22. The filter F22 is a filter that inhibits aninflow of the high-frequency waves to the second power source 82. Thefilter F22 is, for example, an LC filter. The separate terminal of thefilter unit FU is connected to one end of a coil of the filter F22. Thecoil of the filter F22 partially constitutes a wire between the groundof the second power source 82 and the second heater controller 72. Theother end of the coil of the filter F22 is connected to the groundthrough a condenser of the filter F22.

As illustrated in FIG. 7, the first heater controller 71 has a controlcircuit 71 c and a plurality of switching elements SWA. The plurality ofswitching elements SWA are provided on the plurality of wires 71 f,respectively. Each of the plurality of switching elements SWA may be asemiconductor switching element, for example, a triac. The first heatercontroller 71 receives an output (e.g., an alternating current output ofAC 200 V) from the first power source 80, and generates a plurality offirst outputs (e.g., alternating current outputs of AC 200 V) for theplurality of first heaters 26 b. In the first heater controller 71, astate in which the plurality of first outputs are supplied to theplurality of first heaters 26 b and a state in which the supply of theplurality of first outputs is cut off are switched as a state of theplurality of switching elements SWA is switched between a conductivestate and a cut-off state. The states of the plurality of switchingelements SWA are set by the control circuit 71 c. The control circuit 71c may be configured by, for example, a field-programmable gate array(FPGA) or an exclusive circuit.

As illustrated in FIGS. 3 and 7, the stage 16 is provided with aplurality of temperature sensors TS. The plurality of temperaturesensors TS are mounted on the stage 16 so as to measure temperatures ofthe plurality of zones Z1 of the chuck main body 26. For example, theplurality of temperature sensors TS measure, at the rear surface of thechuck main body 26, the temperatures of the plurality of zones Z1. Eachof the plurality of temperature sensors TS is, for example, afluorescent temperature sensor. The plurality of temperature sensors TSare connected to a sensor circuit TC. An output of each of the pluralityof temperature sensors TS is converted into an electrical digital signalfor the sensor circuit TC, that is, a measured value of the temperatureof each of the plurality of zones Z1. The measured value of thetemperature of each of the plurality of zones Z1 is provided to an upperlevel controller UC.

The second heater controller 72 has an inner controller 72 f, a controlcircuit 72 c, and a plurality of switching elements SWD. The pluralityof switching elements SWD are provided on the plurality of wires 72 p,respectively. Each of the plurality of switching elements SWD may be asemiconductor switching element, for example, a photo MOS relay. Thesecond heater controller 72 receives an output (e.g., direct currentoutput of DC 15 V) from the second power source 82 and generates theplurality of second outputs for the plurality of second heaters 26 c. Inthe second heater controller 72, a state in which the plurality ofsecond outputs are supplied to the plurality of second heaters 26 c anda state in which the supply of the plurality of second outputs is cutoff are switched as a state of the plurality of switching elements SWDis switched between a conductive state and a cut-off state. The statesof the plurality of switching elements SWD are set by the controlcircuit 72 c. The control circuit 72 c may be configured by, forexample, an FPGA or an exclusive circuit.

A plurality of resistance elements 72 r are provided on the plurality ofwires 72 p, respectively. The second heater controller 72 further has aplurality of measuring devices 72 m. Each of the plurality of measuringdevices 72 m measures voltage between both ends of each of the pluralityof resistance elements 72 r and measures an electric current flowingthrough each of the plurality of wires 72 p. Measured values of thevoltage and measured values of the electric current acquired by theplurality of measuring devices 72 m are provided to the upper levelcontroller UC through the control circuit 72 c, the inner controller 72f, and an optical bridge OB.

The inner controller 72 f of the second heater controller 72 isconnected to the upper level controller UC through the optical bridgeOB. The inner controller 72 f may be configured by, for example, aprocessor such as a CPU, or an FPGA. The inner controller 72 fcommunicates with the upper level controller UC through the opticalbridge OB and transmits control signals to the control circuit 71 c andthe control circuit 72 c. The upper level controller UC may beconfigured by a microcomputer provided with a processor such as a CPUand a storage device such as a memory. In the plasma processingapparatus 10, set data of an in-plane temperature distribution of thesubstrate W are provided to the upper level controller UC from the maincontrol unit MC.

Based on the set data of the in-plane temperature distribution of thesubstrate W, the upper level controller UC determines targettemperatures of the plurality of zones Z1 and target values of poweramounts per predetermined time of the plurality of second outputs. Theupper level controller UC controls the control circuit 71 c through theoptical bridge OB and the inner controller 72 f so that the plurality offirst outputs of the power amounts (power amounts per predeterminedtime) in accordance with the target temperatures of the plurality ofzones Z1 are supplied to the plurality of first heaters 26 b. Inresponse to the control by the upper level controller UC and the innercontroller 72 f, the control circuit 71 c controls the power amounts ofthe plurality of first outputs to be supplied to the plurality of firstheaters 26 b.

The upper level controller UC performs feedback control of the poweramounts of the plurality of first outputs supplied to the plurality offirst heaters 26 b so as to reduce errors between the targettemperatures of the plurality of zones Z1 and the measured values of thetemperatures of the plurality of zones Z1 which are acquired by theplurality of temperature sensors TS and the sensor circuit TC. Thefeedback control of the power amounts of the plurality of first outputssupplied to the plurality of first heaters 26 b is, for example, PIDcontrol. Further, during the feedback control of the power amounts ofthe plurality of first outputs supplied to the plurality of firstheaters 26 b, the upper level controller UC may obtain errors betweenthe target temperatures of the plurality of zones Z1 and a movingaverage value of the temperatures of the plurality of zones Z1 which areobtained from time-series data of the measured values of thetemperatures of the plurality of zones Z1.

In one exemplary embodiment, the plurality of first outputs of the firstheater controller 71 have substantially the same and constant electricpower. In this exemplary embodiment, the first heater controller 71 isconfigured to control a plurality of first duty ratios. The plurality offirst duty ratios are ratios between predetermined durations (e.g., 100milliseconds) and supply durations for which the plurality of firstoutputs are supplied to the plurality of first heaters 26 b. The upperlevel controller UC assigns the plurality of first duty ratios to thecontrol circuit 71 c through the optical bridge OB and the innercontroller 72 f. The control circuit 71 c switches the respective states(the conductive state and the cut-off state) of the plurality ofswitching elements SWA within a predetermined time in accordance withthe plurality of assigned first duty ratios. Therefore, the supply ofthe plurality of first outputs to the plurality of first heaters 26 band the cut-off of the supply of the plurality of first outputs to theplurality of first heaters 26 b are alternately switched.

The upper level controller UC adjusts the plurality of first duty ratiosso as to reduce the errors between the target temperatures of theplurality of zones Z1 and the measured values of the temperatures of theplurality of zones Z1 which are acquired by the plurality of temperaturesensors TS and the sensor circuit TC. That is, the upper levelcontroller UC performs feedback control of the plurality of first dutyratios. The feedback control of the plurality of first duty ratios is,for example, PID control. Further, during the feedback control of theplurality of first duty ratios, the upper level controller UC may obtainthe errors between the target temperatures of the plurality of zones Z1and the moving average value of the temperatures of the plurality ofzones Z1 which are obtained from time-series data of the measured valuesof the temperatures of the plurality of zones Z1.

The upper level controller UC controls the control circuit 72 c throughthe optical bridge OB and the inner controller 72 f so that theplurality of second outputs in accordance with the target values of thepower amounts per predetermined time, which is determined based on theset data of the in-plane temperature distribution of the substrate W,are supplied to the plurality of second heaters 26 c. In response to thecontrol by the upper level controller UC and the inner controller 72 f,the control circuit 72 c controls the power amounts (power amounts perpredetermined time) of the plurality of second outputs to be supplied tothe plurality of second heaters 26 c.

Based on the plurality of measured values of electric power, the upperlevel controller UC performs the feedback control of the power amountsof the plurality of second outputs. The feedback control of the poweramounts of the plurality of second outputs is, for example, PID control.Each of the plurality of measured values of electric power is theproduct of the measured value of voltage and the measured value ofelectric current which are acquired by the corresponding measuringdevice 72 m among the plurality of measuring devices 72 m. Further, inthe case in which each of the plurality of second outputs is analternating current output, each of the plurality of measured values ofelectric power may be a root-mean-square value obtained from the productof the measured value of voltage and the measured value of electriccurrent which are acquired by the corresponding measuring device 72 mamong the plurality of measuring devices 72 m. In another exemplaryembodiment, each of the power amounts of the plurality of second outputsmay be controlled based on the time-series moving average value of theproduct of the measured value of voltage and the measured value ofelectric current which are acquired by the corresponding measuringdevice 72 m among the plurality of measuring devices 72 m. Further, inthe case in which each of the plurality of second outputs is analternating current output, each of the plurality of measured values ofelectric power may be a time-series moving average value of theroot-mean-square value obtained from the product of the measured valueof voltage and the measured value of electric current which are acquiredby the corresponding measuring device 72 m among the plurality ofmeasuring devices 72 m.

In one exemplary embodiment, the plurality of second outputs of thesecond heater controller 72 have substantially the same and constantelectric power. In this exemplary embodiment, the second heatercontroller 72 is configured to control plurality of second duty ratios.The plurality of second duty ratios are ratios between predetermineddurations (e.g., 100 milliseconds) and supply durations for which theplurality of second outputs are supplied to the plurality of secondheaters 26 c. The upper level controller UC assigns the plurality ofsecond duty ratios to the control circuit 71 c through the opticalbridge OB and the inner controller 72 f. The control circuit 72 cswitches the respective states (the conductive state and the cut-offstate) of the plurality of switching elements SWD within a predeterminedtime in accordance with the plurality of assigned second duty ratios.Therefore, the supply of the plurality of second outputs to theplurality of second heaters 26 c and the cut-off of the supply of theplurality of second outputs to the plurality of second heater 26 c arealternately switched.

The upper level controller UC adjusts the plurality of second dutyratios so as to reduce an error between the target value of the poweramount and the product of the measured value of electric power of eachof the plurality of second outputs and the corresponding second dutyratio among the plurality of second duty ratios. That is, the upperlevel controller UC performs feedback control of the plurality of secondduty ratios. The feedback control of the plurality of second duty ratiosis, for example, PID control. Further, during the feedback control ofthe plurality of second duty ratios, the upper level controller mayobtain an error between the target value and the time-series movingaverage value of the product of the measured value of electric power ofeach of the plurality of second outputs and the corresponding secondduty ratio.

As described above, based on the set data of the in-plane temperaturedistribution of the substrate W, the upper level controller UCdetermines the target values of the power amounts per predetermined timeof the plurality of second outputs. Specifically, the upper levelcontroller UC determines target temperature increase amounts caused bythe plurality of second heaters 26 c based on the set data of thein-plane temperature distribution of the substrate W, and determines thetarget values of the power amounts per predetermined time of the secondoutputs to be supplied to the plurality of second heaters 26 c based onthe target temperature increase amount. For this reason, the upper levelcontroller UC holds in advance a function of converting the temperatureincrease amounts caused by the plurality of second heaters 26 c into thepower amounts per predetermined time of the second outputs to besupplied to the plurality of second heaters 26 c. Hereinafter, atechnique for obtaining a function of converting the temperatureincrease amounts caused by the plurality of second heaters 26 c into thepower amounts per predetermined time of the second outputs to besupplied to the plurality of second heaters 26 c will be described withreference to FIG. 8.

When obtaining the function, the second outputs are provided to theparticular second heaters 26 c, among the plurality of second heaters 26c, which have the temperature sensors TS (hereinafter, referred to as“particular temperature sensors TS”) disposed at lower sides of theparticular second heaters 26 c. Further, in the example illustrated inFIG. 8, the number of particular second heaters 26 c is three. Further,infrared energy within a particular region in the upper surface of thechuck main body 26 above the particular second heater 26 c is acquiredby an infrared camera IRC. Further, the number of particular regions isequal to the number of particular second heaters 26 c. The measuredvalue of the infrared energy within the particular region acquired bythe infrared camera IRC is inputted to the computer PC. A measured valueof a temperature from the particular temperature sensor TS is alsoinputted to the computer PC. Further, in the computer PC, a conversioncoefficient for converting the measured value of the infrared energyinto the temperature from the measured value of the temperature from theparticular temperature sensor TS and the measured value of the infraredenergy within the particular region from the infrared camera IRC ismade.

After the conversion coefficient is made, the second output is providedto the particular second heater 26 c. Further, the infrared energywithin the particular region is measured by the infrared camera IRC. Themeasured value of the infrared energy within the particular regionacquired by the infrared camera IRC is inputted to the computer PC.Further, in the computer PC, the temperature within the particularregion is calculated from the measured value of the infrared energywithin the particular region using the conversion coefficient. Thisprocess is repeated while changing the power amount per predeterminedtime of the second output by changing the aforementioned second dutyratio. Further, based on a relationship between the temperature increaseamount obtained from the calculated temperature of the particular regionand the power amount per predetermined time of the provided secondoutput, a function of converting the temperature increase amount intothe power amount per predetermined time of the second output is obtainedin respect to each of the particular second heaters 26 c.

The upper level controller UC specifies the power amount perpredetermined time of the second output corresponding to the targettemperature increase amount using the obtained corresponding function,thereby determining the target value of the power amount perpredetermined time of the second output supplied to each of theplurality of second heaters 26 c. Further, a function obtained using anyone of the second heaters 26 c is used to determine the target value ofthe power amount per predetermined time of the second output supplied toanother second heater 26 c that is included in the same zone Z1 as anyone second heater 26 c among the particular second heaters 26 c.

In the aforementioned stage 16, the number of first heaters 26 b issmaller than the number of second heaters 26 c. That is, the number offirst heaters 26 b is comparatively small. Therefore, the number ofpower feeding lines for the plurality of first heaters 26 b isdecreased, and a rated electric current of each of the power feedinglines is increased. For this reason, a settable electric power range ofthe first outputs to be supplied to the plurality of first heaters 26 bis widened, and a settable temperature range is widened. In addition,each of the comparatively plurality of second heaters 26 c may bederived by the second output having comparatively low electric power.Therefore, the plurality of second heaters 26 c may precisely controlthe in-plane temperature distribution of the substrate W even thougheach of the plurality of second heaters 26 c has a narrow settabletemperature range. Since the stage 16 has the plurality of first heaters26 b and the plurality of second heaters 26 c, a temperature rangesettable by the stage 16 is wide, and the stage 16 may precisely controlthe in-plane temperature distribution of the substrate W.

In one exemplary embodiment, the plurality of first heaters 26 b areprovided coaxially with respect to the central axis AX. The plurality ofsecond heaters 26 c are provided in the plurality of zones Z2,respectively. The plurality of zones Z2 are provided in the central zonewhich intersects the central axis AX and the plurality of zones whichsurround the central zone and are arranged in the circumferentialdirection within the plurality of regions coaxial with the central axisAX. According to this exemplary embodiment, the temperature distributionin the radial direction of the substrate W is controlled by theplurality of first heaters 26 b, and the temperature distribution in theradial direction and the circumferential direction of the substrate Ware controlled by the plurality of second heaters 26 c.

According to one exemplary embodiment, the plurality of second heaters26 c are provided closer to the upper surface of the chuck main body 26,that is, the surface on which the substrate W is placed than theplurality of first heaters 26 b are to the upper surface of the chuckmain body 26. Therefore, it is possible to further improvecontrollability of the in-plane temperature distribution of thesubstrate W.

In one exemplary embodiment, the plurality of first power feeding lines73, the first heater controller 71, the plurality of second powerfeeding lines 74, and the second heater controller 72 are disposed inthe accommodation space 18 s. According to this exemplary embodiment,since the output is distributed to the plurality of first heaters 26 bin the accommodation space 18 s surrounded by the transmission path forthe high-frequency waves, the number of filters, which are required toinhibit an inflow of the high-frequency waves to the first power source80 from the stage 16, may be reduced. In addition, since the output isdistributed to the plurality of second heaters 26 c in the accommodationspace 18 s, the number of filters, which required to inhibit an inflowof the high-frequency waves to the second power source 82 from the stage16, may be reduced. Therefore, deterioration in impedance properties ofthe filter is inhibited, and a loss of the high-frequency waves isinhibited.

In one exemplary embodiment, the power amounts of the plurality of firstoutputs for driving the plurality of first heaters 26 b are adjusted bythe first duty ratios, and the power amounts of the plurality of secondoutputs for driving the plurality of second heaters 26 c are adjusted bythe second duty ratios. According to this exemplary embodiment, it ispossible to adjust the power amounts of the plurality of second outputsfor driving the plurality of second heaters 26 c without mounting aplurality of power control circuits (e.g., DC/DC converters) in thesecond heater controller 72.

In one exemplary embodiment, the plurality of second outputs to besupplied to the plurality of second heaters 26 c are controlled based onthe product of the measured value of electric power and the second dutyratio or based on the moving average value, instead of based on themeasured values of the temperatures of the zones Z2 in which theplurality of second heaters 26 c are disposed. Therefore, the number oftemperature sensors to be provided in the stage 16 is reduced.

In one exemplary embodiment, the plurality of terminals 26 e and theplurality of terminals 26 f are provided within the outercircumferential region 260 b instead of the substrate mounting region260 a. Therefore, influences of the plurality of terminals 26 e and theplurality of terminals 26 f on the control of the temperature of thesubstrate W are inhibited.

While the various exemplary embodiments have been described above,various modified aspects may be made without being limited to theaforementioned exemplary embodiments. The plasma processing apparatushaving any of the stages according to the aforementioned variousexemplary embodiments may be any plasma processing apparatus such as aninductively coupled plasma processing apparatus or a plasma processingapparatus for creating plasma using surface waves such as microwaves.

From the foregoing, it will be appreciated that various embodiments ofthe present disclosure have been described herein for purposes ofillustration, and that various modifications may be made withoutdeparting from the scope and spirit of the present disclosure.Accordingly, the various embodiments disclosed herein are not intendedto be limiting, with the true scope and spirit being indicated by thefollowing claims.

What is claimed is:
 1. A stage for a plasma processing apparatus,comprising: a power feeder that provides a transmission path configuredto transmit high-frequency waves from a high-frequency power source; andan electrostatic chuck including a conductive base provided above thepower feeder, and electrically connected to the power feeder, and achuck main body provided on the base and configured to hold a substratewith electrostatic attractive force, wherein the chuck main body has aplurality of first heaters provided in the chuck main body to bedistributed on a plane in the chuck main body which is orthogonal to acentral axis of the chuck main body, and a plurality of second heatersprovided in the chuck main body to be distributed on a separate plane inthe chuck main body which is orthogonal to a central axis of the chuckmain body, the number of second heaters being larger than the number offirst heaters, and wherein the stage further includes: a first heatercontroller configured to drive the plurality of first heaters by analternating current output or a direct current output from a first powersource, and a second heater controller configured to drive the pluralityof second heaters by an alternating current output or a direct currentoutput from a second power source.
 2. The stage of claim 1, wherein thefirst heater controller is configured to drive the plurality of firstheaters by the alternating current of the alternating current outputfrom the first power source, and the second heater controller isconfigured to drive the plurality of second heaters by the directcurrent of the direct current output from the second power source. 3.The stage of claim 1, wherein the plurality of second heaters arerespectively provided in a central zone which intersects the centralaxis of the chuck main body and a plurality of zones which surround thecentral zone and are arranged in the circumferential direction within aplurality of regions coaxial with respect to the central axis of thechuck main body.
 4. The stage of claim 3, wherein the plurality of firstheaters are provided coaxially with respect to the central axis.
 5. Thestage of claim 1, wherein the chuck main body has a rear surface whichis a surface facing the base, and an upper surface which is a surfaceopposite to the rear surface, and the plurality of second heaters areprovided between the plurality of first heaters and the upper surface.6. The stage of claim 1, wherein the electric power of the alternatingcurrent output or the direct current output from the second power sourceis lower than the electric power from the first power source.
 7. Thestage of claim 1, further comprising: a plurality of first power feedinglines electrically connected to the plurality of first heaters,respectively; and a plurality of second power feeding lines electricallyconnected to the plurality of second heaters, respectively, wherein thefirst heater controller is configured to produce a plurality of firstoutputs by distributing the output from the first power source and tosupply the plurality of first outputs, which have individually adjustedpower amounts, to the plurality of first heaters through the pluralityof first power feeding lines, respectively, wherein the second heatercontroller is configured to produce a plurality of second outputs bydistributing the output of the second power source and to supply theplurality of second outputs, which have individually adjusted poweramounts, to the plurality of second heaters through the plurality ofsecond power feeding lines, respectively, wherein the power feederdefines an accommodation space surrounded by the transmission path, andwherein the plurality of first power feeding lines, the first heatercontroller, the plurality of second power feeding lines, and the secondheater controller are disposed in the accommodation space.
 8. The stageof claim 7, wherein the plurality of first outputs have substantiallythe same and constant electric power, and the first heater controller isconfigured to control a plurality of first duty ratios which are ratiosof supply durations for which the plurality of first outputs aresupplied to the plurality of first heaters, respectively, relative to apredetermined duration, and wherein the plurality of second outputs havesubstantially the same and constant electric power, and the secondheater controller is configured to control a plurality of second dutyratios which are ratios of supply durations for which the plurality ofsecond outputs are supplied to the plurality of second heaters,respectively, relative to a predetermined duration.
 9. The stage ofclaim 8, further comprising: a plurality of temperature sensors providedto respectively measure temperatures of the plurality of zones in whichthe plurality of first heaters are disposed, wherein the first heatercontroller is configured to adjust the plurality of first duty ratios soas to reduce an error between a target temperature and a measured valueof a temperature measured by each of the plurality of temperaturesensors or to reduce an error between the target temperature and amoving average value obtained from time-series data of the measuredvalue of the temperature measured by each of the plurality oftemperature sensors, and the second heater controller is configured toadjust the plurality of second duty ratios so as to reduce an errorbetween a target value and the product of the measured value of electricpower of each of the plurality of second outputs and the correspondingsecond duty ratio among the plurality of second duty ratios or to reducean error between the target value and a moving average value obtainedfrom time-series data of the product of the measured value of electricpower of each of the plurality of second outputs and the correspondingsecond duty ratio.
 10. The stage of claim 7, wherein the chuck main bodyhas a substrate mounting region in which the substrate is placed, and anouter circumferential region which surrounds the substrate mountingregion from the outside in the radial direction with respect to thecentral axis, and a plurality of terminals, which are electricallyconnected to the plurality of first power feeding lines and theplurality of second power feeding lines, are provided within the outercircumferential region.
 11. The stage of claim 10, wherein the pluralityof terminals are distributed around the entire circumference of theouter circumferential region.
 12. The stage of claim 10, wherein theplurality of second heaters are provided within the substrate mountingregion, and some of the plurality of first heaters are provided at leastwithin the outer circumferential region.
 13. A plasma processingapparatus comprising: a chamber configured for plasma processing; thestage described in claim 1 in which at least the electrostatic chuck isprovided in the chamber; and a high-frequency power source electricallyconnected to the power feeder feeder.
 14. The plasma processingapparatus of claim 13, further comprising: a plurality of first powerfeeding lines electrically connected to the plurality of first heaters,respectively; and a plurality of second power feeding lines electricallyconnected to the plurality of second heaters, respectively, wherein thefirst heater controller is configured to produce a plurality of firstoutputs by distributing the output from the first power source and tosupply the plurality of first outputs, which have individually adjustedpower amounts, to the plurality of first heaters through the pluralityof first power feeding lines, respectively, wherein the second heatercontroller is configured to produce a plurality of second outputs bydistributing the output of the second power source and to supply theplurality of second outputs, which have individually adjusted poweramounts, to the plurality of second heaters through the plurality ofsecond power feeding lines, respectively, wherein the power feederdefines an accommodation space surrounded by the transmission path, andwherein the plurality of first power feeding lines, the first heatercontroller, the plurality of second power feeding lines, and the secondheater controller are disposed in the accommodation space.
 15. Theplasma processing apparatus of claim 14, further comprising: a firstfilter configured to inhibit an inflow of high-frequency waves to thefirst power source, partially constituting a power feeding line betweenthe first power source and the first heater controller and providedoutside the power feeder with respect to the accommodation space; and asecond filter configured to inhibit an inflow of high-frequency waves tothe second power source, partially constituting a power feeding linebetween the second power source and the second heater controller andprovided outside the power feeder with respect to the accommodationspace.